Communication systems are well known and consist of many types including land mobile radio, cellular radiotelephone, personal communication systems, and other communication system types. Within a communication system, transmissions are conducted between a transmitting device and a receiving device over a communication resource, commonly referred to as a communication channel. To date, the transmissions have typically consisted of voice signals. More recently, however, it has been proposed to carry other forms of signals, including high-speed data signals. For ease of operation, it is preferable to have the data transmission capability overlay the existing voice communication capability, such that its operation is essentially transparent to the voice communication system while still utilizing the communication resources and other infrastructure of the voice communication system.
One such communication system currently being developed with transparent data transmission capabilities is the next generation Code-Division Multiple-Access (CDMA) cellular communication system, more commonly referred to as Wideband cdmaOne, or Wideband 95. Within such a communication system all remote unit and base station transmissions commonly occur simultaneously within the same frequency band. Therefore, a received signal at a base station or remote unit comprises a multiplicity of frequency and time overlapping coded signals from individual remote units or base stations, respectively. Each of these signals is transmitted simultaneously at the same radio frequency (RF) and is distinguishable only by its specific encoding (channel). In other words, the signal received at a base-station or remote unit receiver is a composite signal of each transmitted signal and an individual signal is distinguishable only after decoding.
Remote unit data transmission within a Wideband 95 communication system takes place by assigning the remote unit a high-speed data channel (referred to as a supplemental channel) and transmitting data as discussed above utilizing the supplemental channel. More specifically, when data transmission is requested, a remote unit is immediately assigned a common traffic channel (fundamental channel), and is power controlled to the correct transmit power until a supplemental channel is available. Once available, data transmission occurs utilizing the supplemental channel. After transmission, the supplemental channel is dropped by the remote unit, and power control continues on the fundamental channel.
Because the number of channels available within a communication system are limited, data transmission within a Wideband 95 communication system decreases system capacity. In particular, the utilization of a fundamental channel for power control for lengthy periods of time needlessly reduces the number of channels available to the system. Therefore, a need exists for a method and apparatus for data transmission within a broad-band communication system.